Electronic mail (email) is a popular way for people to communicate with one another. When a computer user composes an email message, the email message can be sent to one or more recipients. Each recipient has the option of either replying to the sender's email message, or declining to respond.
Conventional email applications provide a recipient with limited information about other recipients of the same email message. For example, an email message to an employee inviting the employee of attend a meeting includes a list of other participants in the body of the email message. A person receiving an email invitation to an event can reply to all recipients, or to the sender only.